Generally, an upper of a shoe is designed in view of a shape of a foot in a stationary state. However, at the time of exercise (for example, walking, running etc.), the shape of the foot varies continuously in the shoe. That is, at the time of exercise, the foot often comes away from the sole of the shoe, or the upper often prevents the foot from deforming naturally, because the upper cannot deform in accordance with the variation of the shape of the foot. Therefore, considering the upper as a component which makes the sole follow the foot, it is desirable that the upper deforms in accordance with the variation of the shape of the foot.
That is, because the shape of the foot varies at the time of exercises, a shoe is required to have high fitting property with respect to the foot. To improve the fitting property, it is desirable that the strain distribution of the upper resembles that of the foot.
The shoes of the first patent document (Japanese Utility Model Laid-Open No. 4-107608, FIG. 1 therein), the second patent document (Japanese Utility Model (examined) No. 60-18082, FIG. 1 therein), the third patent document (Japanese Patent Laid Open No. 2000-287704, FIG. 2 therein), the fourth patent document (Japanese Utility Model (examined) No. 1-26245, FIG. 1 therein), and the fifth patent document (Japanese Patent Laid Open No. 2000-184902, abstract therein) are known as shoes having improved fitting property.
FIG. 16(a) shows the shoe disclosed in the first patent document. In this shoe, a part of the lateral side of an upper U is formed with elastic member 100.
FIG. 16(b) shows the shoe disclosed in the second patent document. In this shoe, a part of both sides of an upper U is formed with elastic member 100.
FIG. 16(c) and FIG. 16(d) show the third patent document. In this shoe, both sides of a front part of an upper U are formed with elastic member 100.
FIG. 17(a) shows the shoe disclosed in the fourth patent document. In this shoe, a part of an upper U anterior to an opening is formed with bendable member 100.
FIG. 17(b) shows the shoe disclosed in the fifth patent document. In this shoe, a notched portion 102 in wedge shape is formed with stretchable member 100. The notched portion 102 extends shortly from the opening 103 of the upper U.